There is no system in the 21st century that has no vulnerability. Most networks seem to be very secure because the vulnerabilities in them are yet to be discovered. However, these vulnerabilities decrease in networks that undergo regular checks and upgrade in their directories with embedded security parameters which have cryptographic primitives. Lack of network checks has fashioned various attack vectors, which hackers exploit to break into the security of private, public and even virtual networks. Network attacks such as brute forcing, Man-in-the-Middle (MITM) attack, social engineering and Advanced Persistent Threats (APT) occur as a result of the combinations of several vulnerabilities which are embedded in them. The aim of this paper is to discover vulnerabilities such as weak passwords on networks and to demonstrate some common attacks that are frequently carried out on vulnerable networks which lack strong security primitives. Basic attacks demonstrated in this research were MITM attack, Address Resolution Protocol (ARP) poisoning, Dynamic Host Configuration Protocol (DHCP) starvation attack and brute forcing. This research was conducted using network attack tools such as Nmap and Ethercap which are attack tools in kali Linux. The results showed that the vulnerabilities on networks range from poor embedment of security parameters on networks, opened network ports, weak and unsalted passwords and a host of others.

Description

To have an enduring system that could stand the test of the current attacks and threats, which are perpetrated on internet nowadays, organizations must have a continual
up-to-date of all the security primitives and auditory parameters (Osei-Bryson and Carter, 2017) in place. Security auditing is the bedrock of every risk assessment on any network, be it public, private or virtual (Alhakami, 2016). The security of network is a fast moving and fashionable area. The fashionable ideas behind it are that networks can be secured by firewalls for blocking unwanted or suspected network traffic. But all these ideas in place do not provide everlasting solution to cyber attacks such as password fishing (Belani et al., 2016; Chaudhry et al., 2016; Leukfeldt et al., 2016; Tewari et al., 2016; and Tian et al., 2016) Man-in-the-Middle (MITM) attack (Conti et al., 2016 and Athavale et al., 2017), social engineering (Beutel et al., 2013; Krombholz et al., 2015; and Stembert et al., 2015), unpatched software, Advanced Persistent Threats (APT) (Moon et al., 2017), hijacking and distribution of malwares. Most of these attacks occur as a result of the combination of several vulnerabilities (Sinnaya et al., 2013) which are involved in these networks. Most networks are outside the control of network administrators, managers and the security parameters (Klein and Kliger, 2016). Examples of these vulnerabilities include weak usernames and passwords, vulnerable CGI programs on web servers, a stack overflow attack on the Remote Procedure Call (RPC) mechanism, a bug in Microsoft’s Internet Information Server (IIS) web server software, a stack overflow attack on Sun’s Solaris operating system and weak authentication in the Simple Network Management Protocol (SNMP) protocol (Yan et al., 2017).